Analysis of Influence Factors and Rules of Transformer Neutral Point DC

When DC transmission system adopts monopole earth or bipolar imbalance operation mode, the DC grounding electrode will inject large amount of current into the earth, and then disturb the running of the power grid. In view of the influence which is created by DC transmission system in Guangdong power grid, this paper derived the mathematical expressions of the transformer neutral point current after creating a calculation model, and concluded the main influence factors; The subject applied the linear regressing analysis theory to calculate the regression equations of transformers so that the slope of the regressing equation can be used to estimate the influence scope of grounding DC. Finally it concludes that: transformer neutral point current and the power transmitted by DC system has positive correlation; For ±800kV DC Chu Sui, the transformers ,which is more than 80 km away from DC grounding electrode, will no longer be affected; The application of DC suppression devices will affect the neutral point current of the transformers nearby.

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10kV Grid Arc Grounding Over-Voltage Hazards and Countermeasures

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.392.489 ◽

2013 ◽

Vol 392 ◽

pp. 489-493

Author(s):

Qing Hao Wang ◽

Zi Jun Huang ◽

Zhi Gang Li ◽

Bo Fang ◽

Gui Bin Hu

Keyword(s):

Single Phase ◽

Power Grid ◽

Operation Mode ◽

Scientific Basis ◽

Neutral Point ◽

Correct Selection ◽

Capacitive Current ◽

Current Test ◽

Selection Of

Through the analysis of 2 single-phase grounding over voltage accidents caused by capacitive over current in 10 kV power grid in this paper, the causes and damages of arc grounding over voltage are illustrated, and the necessity of capacitive current test and effective methods are pointed out. The test and assessment to the 29 substations capacitor currents provides a scientific basis for the correct selection of the neutral point operation mode, and the strengths and weaknesses of the neutral Point grounding through the arc suppression circle and the mode trends of 10kV grid neutral grounding are demonstrated.

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The Calculation Method of Basic Reserve Fund in Power Grid Construction Project: A Case Study from China

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.584-586.2659 ◽

2014 ◽

Vol 584-586 ◽

pp. 2659-2663

Author(s):

Xue Liang Hou ◽

Ying Rong Yang ◽

Yue Li

Keyword(s):

Calculation Method ◽

Power Grid ◽

Construction Project ◽

Influence Factors ◽

Measuring Method ◽

Calculation Model ◽

Distribution Fitting ◽

Fixed Rate ◽

Grid Construction ◽

Reserve Fund

This paper studied the calculation method of basic reserve fund (BRF) based on distribution fitting and Monte Carlo Simulation (MCS) in power grid construction project (PGCP). BRF copes with the various unforeseen expenses in the process of budget compilation. Nowadays, the measuring method with fixed rate cannot adapt to the request, because of the BRF with larger uncertainty influence factors. MCS technique can achieve a good simulation to solve the problem of uncertainty. The research first uses MINITAB to analysis the distribution of various influence factors, then uses MATLAB to build calculation model to take the stochastic simulation for many times, finally gets a more realistic BRF. A case from China is used to confirm this calculation method works well.

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Asymmetric Fault Current Distribution on OPGW in Overhead Transmission System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1092-1093.244 ◽

2015 ◽

Vol 1092-1093 ◽

pp. 244-247

Author(s):

Zheng Qi ◽

Zhi Rao ◽

Shou Kui Zhang ◽

Zhi Li

Keyword(s):

Current Distribution ◽

Calculation Method ◽

Operation Mode ◽

Calculation Model ◽

Transmission System ◽

Fault Current ◽

Phase Component ◽

Engineering Projects ◽

Fault Current Distribution

This paper discusses a phase component calculation model of current distribution on OPGWs when asymmetric fault occurs. The calculation is based on analysis of electric and magnetic environment and experience of actual engineering projects. Influences of some factors such as the operation mode of OPGW and resistance of power tower are mentioned to find out their influence on fault current distribution. These are applied in an actual engineer project. The calculation method is benefit for the verifying and selecting of OPGW.

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